1. I've been trying to do a shrink fit between a simple cylindrical hub and a round shaft (using ASM).
2. I've been using solid brick elements for both parts.
3. I draw the parts assembled in inventor with 0.15 mm radial interference
4. I import into ASM
5. I mesh with 8 node bricks
6. I change bonded contact to shrink fit/no sliding
7. I enter radial interference as 0.15 mm
8. I solve with either sparse solver or automatic
9. I get the message 'not tied down properly'
10. The solution will not finish
I've spent quite a while on this. Could someone please give some suggestions on shrink fits? I've used Inventor for this without a problem!
Did you apply any boundary condition / constraint to your model?
Looks like that’s what you are missing for your setup
Sualp Ozel, PE
Hi and thanks for replying.
Yes, I've used a BC. I've tried all sorts on fact.
Since I posted this, I'm getting a result but not a correct one.
-Hub is a simple Hollow cylinder, OD = 216mm, ID = 139.85 mm with 135 mm axial length
-Shaft is solid and is 140 OD by 300 long with keyway
-Static Linear Stress Analysis
-0.075mm radial interference
-friction set to 0.25
-Surface contact direction = normal to first part/surface
-Direction Tolerance Angle = 10
-Shrink Fit / Sliding
-iteration - mixed
-stiffness reduction attempts 2
Mesh on Both Parts
-4 mm tets, 2nd order Or 6mm bricks
Radial Stress at ID = -550 N/mm^2 (should be -62 N/mm^2)
Radial Stress at Od =0 (Ok)
Axial Stress at ID = 1550 N/mm^2 (should be 152 N/mm^2)
Radial Stress at Od = -650 N/mm^2 (Should be -62 N/mm^2)
Axial Stress at ID = -350 N/mm^2 (should be -62 N/mm^2)
The results are close to 10 x too high.
I created the same setup using Inventor and ASIM-Mech 2013. the only difference in my design was the contact type. I used Shrink fit without sliding so that the model becomes stable. also using this contact type i was able to compare the results i get from Asim-Mech to Inventor-Sim. I am attaching my results images. You will see that with this setup the results for both software are very similar. I will also try to attach the Inventor part/assembly files along with the ASIIM-Mech Archive file to this post. Hope this helps